• The Korean Journal of Physiology and Pharmacology
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• 제10권3호
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• pp.137-141
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• 2006

The systolic and diastolic pressures in anesthetized Sprague-Dawley male rats were greatly decreased after single-dose of Cd treatment without significant changes in heart rate. There was a fluid-shift into the third space and/or -loss through the kidney, since plasma $Na^+$ concentration and hematocrit ratio were significantly increased by acute Cd exposure. The present study showed that the sustained hypotensive effect of single-dose Cd on the cardiovascular system might have resulted from the systemic hypovolemia. Furthermore, renal excretion of electrolytes, including $Na^+$ and $K^+$, and urine flow rate were increased by Cd intoxication. Interestingly, the ratio of $Na^+/K^+$ excretion was increased and reached the maximum level 3 hours after Cd injection and returned to the normal level after 7 hours. Nevertheless, there was no difference in the regression analysis of $Na^+$ excretion and urine flow rate in both groups. Therefore, the increase in the urine volume seemed to enhance the excretion of $Na^+$. This study strongly suggest that the hypotensive effect of Cd is mediated by systemic $Na^+$ loss through the kidney and/or hypovolemia via fluid-shift.

• 약학회지
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• 제31권6호
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• pp.376-393
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• 1987

This study was performed in order to investigate the effect of nifedipine, a vasodilating drug which acts through calcium antagonism, on renal function using mongrel dog. Nifedipine, when given interavenously in doses ranging from 1.5 to 5.0$\mu\textrm{g}$/kg, elicited diuresis along with less changes of glomerular filtration rate and significant increases of renal plasma flow, so that the filtration fraction(FF) decreased significantly, at the same time both osmolar and free water clearances increased, and amount of sodium, potassium and calcium excreted in urine increased significantly. Nifedipine, when infused into a renal artery in doses from 0.05 to 0.15$\mu\textrm{g}$/kg/min, exhibited identical responses to the actions of intraveneous nifedipine except significant increase of glomerular filtration rate and no change of FF, which was confined only to the infused kidney. The renal action of nifedipine into a renal artery were not influenced by renal denervation, decreased significantly by ouabain, Na$^+$-K$^+$-ATPase inhibitor, which was given into a renal artery. Nifedipine infused into a renal artery in dog pretreated with propranolol i.v. produced diuresis associated with the increase of electrolytes excretion by reduction of electrolyte reabsorption and with no changes of glomerular filtration rate and renal plasma flow. Thus, it is concluded that nifedipine infused into a renal aretery produces diuretic action along with both improvement of hemodynamics and inhibition of electrolytes reabsorption, which may be related to sympathetic $\beta$-receptor or Na$^+$-K$^+$-ATPase activity because the action of nifedipine in kidney is blocked by propranolol or ouabain.

• The Korean Journal of Physiology
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• 제23권2호
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• pp.363-375
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• 1989

It has been well known that peripheral infusion of angiotensin II results in an increase of blood pressure, and an elevation of aldosterone secretion, and an inhibition of renin relase. However, the direct effect of angiotensin II on renal function has not been clearly established. In the present study, to investigate the effect of angiotensin II on renal function and renin release, angiotensin II (0.3, 3 and 10 ng/kg/min) was infused into a unilateral renal artery of the unanesthetized rabbit and changes in renal function and active and inactive renin secretion rate (ARSR, IRSR) were measured. In addition, to determine the relationship between the renal effect of angiotensin II and adenosine, the angiotensin II effect was evaluated in the presence of simultaneously infused 8-phenyltheophylline (8-PT, 30 nmole/min), adenosine A 1 receptor antagonist. Angiotensin II infusion at dose less than 10 ng/kg/min decreased urine flow, clearances of para-amino-hippuric acid and creatinine, and urinary excretion of electrolytes in dose-dependent manner. The changes in urine flow and sodium excretion were significantly correlated with the change in renal hemodynamics. Infusion of angiotensin II at 10 ng/kg/min also decreased ARSR, but it has no significant effect on IRSR. The change in ARSR was inversely correlated with the change in IRSR. The plasma concentration of catecholamine was not altered by an intarenal infusion of angiotensin II. In the presence of 8-PT in the infusate, the effect of angiotensin II on renal function was significantly attenuated, but that on renin secretion was not modified. These results suggest that the reduction in urine flow and Na excretion during intrarenal infusion of angiotensin II was not due to direct inhibitions of renal tubular transport systems, but to alterations of renal hemodynamics which may partly be mediated by the adenosine receptor.

• 대한약리학회지
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• 제22권2호
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• pp.79-87
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• 1986

중추 dopamine(DA)계가 신장기능 조절에 관여하고 있으며 뇌실내로 DA를 투여하면 norepinephrine(NE)처럼 항이뇨와 항Na 배설을 초래함이 보고된 바 있고, 중추 DA작용에 있어서 adrenergic system이 관여한다는 많은 시사가 있다. 따라서 본 연구에서는alpha-2 adrenocopter 차단제인 yohimbine이 측뇌실내 DA의 신장작용에 어떠한 영향을 미치는가를 관찰하였다. Yohimbine $100\;{\mu}g/kg$을 가토측뇌실내로 투여시(icv) 신혈류 및 사구체 여과율의 감소와 함께 현저한 항이뇨 및 Na 배설감소를 초래하였으며, DA $15\;{\mu}g/kg$ icv 역시 항이뇨를 초래하였으나 yohimbine 전 처치후에는 뇨량 및 Na배설의 증가를 초래하였다. 양을 더올려 $150\;{\mu}g/kg$의 DA를 yohimbine 전처치 가토에 투여하면 3배 이상의 Na배설 증가와 함께 현저한 이뇨작용이 나타났으며 이 작용은 약 20분간 지속되었다. 이때 신혈류 역학은 일부 개선되었다. 다른 DA agonist인 apomorphine은 $100\;{\mu}g/kg$ icv로 현저한 이뇨와 Na 배설증가를 나타내며 신혈류역학도 개선하였으나, yohimbine은 이같은 apomoiphine작용을 차단하지 못하였다. NE $10\;{\mu}g/kg$ icv도 항이뇨 작용을 나타냈으나 yohimbine 전처치에 의하여 차단되지 아니하였다. 이 연구결과로, 중추 DA의 신장작용은 NE처럼 단순하지 않고, 이뇨작용은 신혈류역학의 감퇴에 기인한 항이노작용에 의해 은폐되어 있으며, yohimbine은 DA의 항이뇨작용은 차단하나 이뇨작용에는 영향을 미치지 못하며, DA의 항이뇨작용이 지양될때에만 이뇨작용이 발현됨을 알 수 있었다. 또한 중추를 통한 DA의 신장작용에는 adrenergic system이 관여하지 않은 것으로 보인다.

• The Korean Journal of Physiology
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• 제16권2호
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• pp.159-163
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• 1982

Vasoactive intestinal peptide (VIP) found in duodenal mucosa originally has been suggested as a neurotransmitter. Its localization, however, now known, is not limited to the gastrointestinal tract, but scattered at many different kinds of tissues, smooth muscles, endocrine gland and exocrine gland as well as central and peripheral neural tissues. To investigate the effect of VIP on renal function, an experiment has been done in anesthetized male rats. The results obtained were: 1) Urinary output and creatinine clearance decreased significantly during the period of infusion of VIP, 2.0ug/rat/7minutes. 2) Urinary excretion of sodium, potassium and chloride decreased but without significance by infusion of VIP. 3) Blood pressure, systolic and diastolic, decreased by VIP administered intravenously in the period of infusion. 4) Changes of urinary output, sodium and chloride excretion was correlated with changes of creatinine clearance. The above data suggest that VIP administered intravenously can suppress the renal hemodynamics indirectly, and also decrease electrolyte excretion through its renal hemodynamic change.

• 대한핵의학회:학술대회논문집
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• 대한핵의학회 1972년도 제11차 학술대회
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• pp.68.2-68.2
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• 1972

• Biomolecules & Therapeutics
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• 제9권3호
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• pp.209-217
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• 2001

This study was attempted to investigate on renal effect of ($\pm$)6-chloro-7,8-dihydroxy-1-phenol 2,3,4,5-tetrahydro-lH-3 benzazepine (SKF 81297), dopamine $D_1$ receptor agonist, in dog. SKF 81297, when gluten intravenously, produced diuretic action along with the increases of renal plasma flow (RPF), glomerular filtration rate (GFR), amounts of N $a^{+}$ and $K^{+}$ excreted into urine ( $E_{Na}$ , $E_{K}$) and osmolar clearance ( $C_{osm}$). It also decreased the reabsorption rates of N $a^{+}$ and $K^{+}$ in renal tubule ( $R_{Na}$ , $R_{K}$) and free water clearance ( $C_{H2O}$), whereas ratios of $K^{+}$ agonist N $a^{+}$ in urine and filtration fraction (FF) was not changed. SKF 81297, when administered into a renal artery, elicited diuresis both in experimental kidney given the SKF 81297 and control kidney not given, while the effect was more remarkable in experimental kidney than those exhibited in control kidney. SKF 81297 given into carotid artery also exhibited diuresis, the potency at this time, compared to those induced by intravenous SKF 81297, was magnusgreat. Above results suggest that SKF 81297 produces diuresis by both indirect action through changes of central function and direct action being induced in kidney. Central diuretic action is mediated by improvement of renal hemodynamics, but direct action by inhibition of electrolytes reabsorption in renal tubule.enal tubule. tubule.

• Journal of Gastric Cancer
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• 제20권3호
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• pp.256-266
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• 2020

Purpose: This study aimed to examine the early postprandial changes in gastrointestinal (GI) hormones and hemodynamics in terms of early dumping syndrome after gastrectomy for gastric cancer. Materials and Methods: Forty patients who underwent gastrectomy for gastric cancer and 18 controls without previous abdominal surgery were enrolled. Before and 20 minutes after liquid meal ingestion, blood glucose, glucagon-like peptide-1 (GLP-1), and GLP-2 concentrations and superior mesenteric artery (SMA) and renal blood flow were measured. The patients' heart rates were recorded at 5-minute intervals. All subjects were examined for dumping syndrome using a questionnaire based on Sigstad's clinical diagnostic index. Results: The postprandial increases in blood glucose, GLP-1, and GLP-2 levels as well as SMA blood flow and heart rate were greater in patients who underwent gastrectomy than in controls (all P<0.010). Patients who underwent gastrectomy showed a significantly decreased renal blood flow (P<0.001). Among patients who underwent gastrectomy, distal gastrectomy was a significant clinical factor associated with a lower risk of early dumping syndrome than total gastrectomy (hazard ratio, 0.092; 95% confidence interval, 0.013-0.649; P=0.017). Patients who underwent total gastrectomy showed a greater postprandial increase in blood glucose (P<0.001), GLP-1 (P=0.030), and GLP-2 (P=0.002) levels as well as and heart rate (P=0.013) compared to those who underwent distal gastrectomy. Conclusions: Early postprandial changes in GI hormones and hemodynamics were greater in patients who underwent gastrectomy than in controls, especially after total gastrectomy, suggesting that these changes play a crucial role in the pathophysiology of early dumping syndrome.

• The Korean Journal of Physiology
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• 제19권1호
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• pp.25-33
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• 1985

Renal arterial infusion of renotropic agents has been a very useful technique in the renal function studies. This type of experiments have usually been conducted in the large animals such as dogs and sheep. In these animals a catheter can be placed in the site without much disturbances of renal blood flow. Rabbits as an experimental model, however, caused a disturbances of renal blood flow by a catheterization of renal artery by its properties. Therefore we have developed a new technique that allows a simple and selective access to one side of renal arteries and the other as a control, without any disturbances of renal function. The distance between the both bifurcations of renal arteries on abdominal aorta is about 7 mm. To locate the tip of catheter on one side renal artery, ascending cannulation performed via femoral artery was done. We did an experiment with the technique to clarify the effect of calmodulin inhibitor on the renal function. One of the phenothiazine derivatives, trifluoperazine known as a powerful calmodulin inhibitor. Trifluoperazine, actual dose ranges of $2.76-5.20\;ug\;{\cdot}\;kg^{-1}\;{\cdot}\;min^{-1}$, increased urine volume and glomerular filtration rate significantly. Significant increases in urinary excretion of sodium, chloride and potassium were found. Fractional excretion of sodium and free water clearance increased significantly. These data suggest that this new technique is very useful in field of renal physiology and that striking effect of trifluoperazine on the renal function may be caused by increasing the renal hemodynamics, and by the inhibition of sodium, chloride and potassium reabsorption in the renal tubules.

• The Korean Journal of Physiology
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• 제24권1호
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• pp.131-144
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• 1990

It is well known that the atrial natriuretic peptide (ANP) has a prepro-hormone of 151 amino-acids which loses their hydrophobic signal peptide to form 126 amino acid prohormone. The whole prohormone is released and then cleaved by proteases into more than one circulating forms. Recently, Winters et al. (1988a, b) reported that high concentrations of N-terminal fragments of prepro-ANP $(26{\sim}55),\;(56{\sim}92)\;and\;(104{\sim}123)$ were detected in human plasma. However, their physiological roles have not been established. The present study was conducted to determine whether the N-terminal fragments of pro-ANP have any effect on the renal function and to compare the effect with those of G-terminal fragments of pro-ANP The results indicate that intrarenal arterial infusions of prepro-ANP $(26{\sim}41),\;(26{\sim}55),\;(56{\sim}92)\;and\;(104{\sim}123)$ induced no significant changes in renal function. Whereas ${\alpha}-human$ ANP $(prepro-ANP,\;124{\sim}151)$ and pro-ANP caused a significant increase in urine volume, renal plasma flow, glomerular filtration rate, urinary excretions of sodium, chloride and potassium, and fractional excretion of sodium. These results suggest that the N-terminal fragments of pro-ANP are ineffective, while the C-terminal fragments retain the natriuretic and diuretic activities.